Combination-square



(No Model.)

S. H. BBLLOWS.

COMBINATION SQUARE.

No. 249,821. Patented Nov. 22,1881.

Fly 2] \UNITED STATES PATENT OFFICE.

STEPHEN H. BELLOWS, OF ATHOL, MASSACHUSETTS.

COMBINATION-SQUARE.

SPECIFICATION forming part of Letters Patent No. 249,821, dated November22, 1881.

Application filed February4, 1881. (NomodeL) To all whom it may concernBe it known that I, STEPHEN H. BELLoWs, of Athol, in the countyot'Woreester and State of Massachusetts, have invented a certain new anduseful Improvement in Com bination- Squares, of which thefollowingisadescription, reference being bad to the accompanyingdrawings, wherein-Figure 1 is a side view of a combinationsquare embodying my saidimprovement. Fig. 2 is a view of same in vertical cross-section on plane00 m, Fig. 1. Fig. 3 is a side view of a portion of the instrument,modified by addition of a spirit-level.

The letter A denotes a metallic block, base, or frame bearing a mortise,b, for the reception of the graduated sliding blade 0, one side, b,ofwhich mortise is a seat for such blade, which, when the 'blade restsagainst it, maintains the blade in proper relation to all the arms,hereinafter described, which are fixed to the base A.

The letter adenotes aright-angular arm fixed to the base A, by means ofwhich the instrument is usable as a common try-square. (I denotes anarm, by which bevel or miter lines can be made, and therefore called abevel-arm. e and 0 denote two arms fixed to the base A, which can beused to find the center of shafts and the like, and therefore calledcenteringarms.

The base A is composed of two separate parts or base-sections, a and a,which are riveted together, as indicated in dotted lines. It will beobserved that the seat for the blade I) is a part of that face ofbase-section a which meets a corresponding face of section a. Said face,which is the seat I), can be readily and cheaply made true, when exposedfor work thereon, before the two base-sections are fastened together,and the mortise b can be readily and cheaply made in base-section a,when said face thereof is exposed, before the two sections are fastenedtogether. To make mortise I) and seat I) by broaehing or the likethrough a solid piece of suitable metal would be difficult andexpensive. The blade is fastened at any desired point in base A by meansof the setecrew f, having a shoe, g in termediate between it and theblade, also the compression helical spring h, acting from the screw tothe shoe. The inner end of the shoe g is frusto-conical, and it lies ina round socket, 43, which will not permit it to project so far into thepath of the blade (this when the blade is out of .the base) that the endof the blade (in replacing it) can strike against the vertical side oftheshoe, but (in thus replacing the blade) it will strike the conicalface of the shoe, and thus force it back so that the blade can pass. Thepressure of the spring h, when the screw is slightly loosened, keeps theblade against its seat, so that it does not drop out of the baseaccidentally, nor permit dirt to get between the blade and its seat.

It will be observed that this organization of parts attains thedesideratum of a screw, which, bearing on the edge of the blade, pushesthe blade to its seat rather than pulls it, though a clamp-bolt pullingthe blade to its seat can be used in the place of the set-screw and bean equivalent therefor, except as to the special advantage just named.

I claim as my improvement 1. The base A, bearing the right-angular arm0, bevel-arm d, centering-arms e e, and blade-seat I), common to all thearms, in combination with the sliding blade and the setscrew, allsubstantially as described, and for the purpose set forth.

2. The base-sections a, bearing the arms d e and blade-seat I), joinedto the base-section a,bearing the arms 6 e and mortiseb,andcombined withthe blade and set-screw, all substantiall y as described, and for thepurpose set forth.

3. In combination, the mortised base A, the sliding blade 0, the beveledshoe g, and the set-screw, all substantially as described, and for thepurpose set forth.

In witness whereof] hereto set my hand this 31st day of January, A. D.1881.

W. E. SrMoNns, JAMES J. GREENE.

